Given an array of distinct integers and a target sum, find two numbers in the array that add up to the target sum.

TwoSum.java

public class TwoSum {
    public static int[] twoSum(int[] a, int sum) {
        for (int i = 0; i < a.length; i++) {
            for (int j = i + 1; j < a.length; j++) {
                int x = a[i];
                int y = a[j];
                if ((x + y) == sum) {
                    return new int[]{x, y};
                }
            }
        }

        return null;
    }

    public static void main(String[] args) {
        int[] numbers = {3, 9, 1, 15, 10};
        int sum = 13;
        var nums = twoSum(numbers, sum);
        if (nums != null) {
            System.out.println(nums[0] + " + " + nums[1] + " = " + (nums[0] + nums[1]));
        }
    }
}